Measurement of the CP violation parameters in B-0 -> pi(+) pi(-) decays

Abstract

We present a measurement of the charge-parity (CP) violating parameters in B-0 -> pi(+) pi(-) decays. The results are obtained from the final data sample containing 772 x 10(6) B (B) over bar pairs collected at the Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric-energy e(+) e(-) collider. We obtain the CP violation parameters A(cp)(B-0 -> pi(+) pi(-)) = +0.33 +/- 0.06(stat) +/- 0.03(syst), S-cp(B-0 -> pi(+) pi(-)) = -0.64 +/- 0.08(stat) +/- 0.03(syst), where A(CP) and S-CP represent the direct and mixing-induced CP asymmetries in B-0 -> pi(+) pi(-) decays, respectively. Using an isospin analysis including results from other Belle measurements, we find 23.8 degrees < phi(2) < 66.8 degrees is disfavored at the 1 sigma level, where phi(2) is one of the three interior angles of the Cabibbo-Kobayashi-Maskawa unitarity triangle related to B-u,B-d decays.